ESS quit after hailstorm

[Chupacabra]

I know this would be a blessing for most, but after I got hit by that nasty hailstorm I've noticed my ESS has never turned the engine off since then. I've looked under the hood, nothing seems out of the ordinary. I've even wondered if the constant impacts on the hood could have shattered the innards of one or both of those goofy pin switches under the hood that tells it if the hood is open or not?

I was watching the battery voltage on the dash display and did notice it never goes over 14.0 even under acceleration. At times when cruising it drops to 13.8-13.9. If I check the ESS status on the main screen, it just says Stop/Start Not Ready but gives no other details.

So ordinarily I'd be OK with ESS just staying off but I'm concerned that something else is wrong and I'd like to figure out what's going on. Does the voltage seem low to anyone else? Has anyone else had ESS just go AWOL for no apparent reason?

My Jeep is stock, no tuners/programmers or anything on it.

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[GtX]

You're reading the alternator voltage, not battery, when the rig is running.
Put a battery charger on it for a few days then see if the ESS will work again.

 

[Chupacabra]

You're reading the alternator voltage, not battery, when the rig is running.
Put a battery charger on it for a few days then see if the ESS will work again.

Yeah I know that, but it still seems like it should be higher than 13.9-14v when the vehicle is running. I disconnected the positive terminal and both batteries read about 12.5-12.6 even after sitting a while.

I'll try throwing my Battery Tender on it overnight and see if it works for a while in the morning.

 

[Chupacabra]

You're reading the alternator voltage, not battery, when the rig is running.
Put a battery charger on it for a few days then see if the ESS will work again.

I left my Duracell battery tender on it overnight. At first it was showing only 50% charged, but my voltmeter said 12.5 when I started.

Anyway, in the morning it said 100% charge and as soon as I took off the charger I measured 12.9 v at the battery terminals.

ESS has been working normally today, although I've only had 3-4 stops where it would normally kick in and it kicked in every time. So you are correct in that it appears to voltage related I'd say.

I'm still concerned that when driving the battery voltage display never goes over 14.0. I'm quite sure it used to go to like 14.2-14.6 when driving. I suspect maybe my alternator is dying because 14.0 seems kind of low to me, and eventually I'm sure the batteries will drop enough again to where ESS quits working.

It's not the ESS not engaging that bothers me, it's WHY it's not engaging and I suspect I have a charging issue.

 

[GtX]

Or, your batteries are failing.
Or, you have a parasitic draw.
Or, you don't drive your rig enough.
Or, you don't drive your rig long enough.

Based on the typical issue most people face your batteries are failing.

 

[Chupacabra]

Or, your batteries are failing.
Or, you have a parasitic draw.
Or, you don't drive your rig enough.
Or, you don't drive your rig long enough.

Based on the typical issue most people face your batteries are failing.

It's my daily driver, nothing has changed in the last year. This started, perhaps coincidentally, after I got nailed in a nasty hailstorm. Probably just a coincidence but that's when I noticed that ESS wasn't working.

Can anyone else look at their battery voltage when you're driving and tell if 13.9-14.0 is typical? I swear it was higher than that when I looked at it once in a while - like 14.2 to 14.6?

Tonight on the highway at 75 MPH the voltage reading was 13.7, which seems awfully low to me when the engine is running.

I think it has to be either the alternator is failing, or one or both batteries are failing myself.

 

[WranglerMan]

This is normal if batteries are healthy and the jeep is not parked a lot

 

[JimLee]

It's my daily driver, nothing has changed in the last year. This started, perhaps coincidentally, after I got nailed in a nasty hailstorm. Probably just a coincidence but that's when I noticed that ESS wasn't working.

Can anyone else look at their battery voltage when you're driving and tell if 13.9-14.0 is typical? I swear it was higher than that when I looked at it once in a while - like 14.2 to 14.6?

Tonight on the highway at 75 MPH the voltage reading was 13.7, which seems awfully low to me when the engine is running.

I think it has to be either the alternator is failing, or one or both batteries are failing myself.

On these smart charging systems the alternator puts out less under load, not more. It's to reduce load on the engine and give an extra millionth of an MPG. When you are slowing down or stopped it usually goes up.

 

[WranglerMan]

As @JimLee stated this is how it’s designed, looking at the voltage gage will drive a person crazy with the way the voltage “dances” if you leave your Jeep parked a lot and not on some type of maint charge you will see 14+ a lot but on a long drive it will slowly drop and will drop quicker if you have the upgraded alternator but if you are seeing the voltage pegged at 14+ and it’s been kept on a charger and driven a lot you have other issues that need to be addressed like possibly a new battery, my stock battery only lasted 7 months and don’t get me started on the IBS module which can also have issues.

 

[MtCamper]

Keep that battery tender handy. My guess is you are going to be replacing the baby battery soon. Good news is you will be covered under warranty. Bad news is the Genesis system will set you back about a grand.

 

[GtX]

Keep that battery tender handy. My guess is you are going to be replacing the baby battery soon. Good news is you will be covered under warranty. Bad news is the Genesis system will set you back about a grand.

This right here

 

[Chupacabra]

Thanks everyone! Tonight when driving home it went up to 14.2v in almost all traffic conditions, and ESS kicked in every time. I know that small battery is a PITA to get to, but so is going to the dealer and leaving it for a day (or more) and then going back for it.

I will look at some of the DIY videos and see if I just want to do it myself and save the hassle of a dealer visit.

 

[rent]

@Chupacabra Which engine configuration do you have? eTorque, manual?

 

[Chupacabra]

@Chupacabra Which engine configuration do you have? eTorque, manual?

I have a 2021 2.0 automatic, no eTorque.

 

[WranglerMan]

A cost effective way of dealing with it is running with one battery, there are several working easy hacks that address this, I chose a different route as I wanted more power.

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